Self-sealing wrapper



W. N. M DONALD.

SELF

Jan. 2, 1940.

SEALING WRAPPER 4 Sheets-Sheet 1 Filed Oct '19, 1936 JanQZ, 1940. w,MacDQNALD 2,185,469

SELF-SEALING WRAPPER Filed Oct. 19, 1936 4 Sheets-Sheet 2 INV NTOR.

MAUI-MM Jaruz, 1940. w, MacDONALD 2,185,469

SELF-SEALING WRAPPER Filed Oct. 19, 1956 4 Sheets-Sheet 3 you y INV OR.BYJ

ATTORNEY.

Jan. 2, 1940. w, N, MMDONALD 2,185,469 v -SELF SEALING WRAPPER FiledOct. 19, 1936 v 4 Sheets-Sheet 4 WAX APEA'. WAX /O v /2 INVENTOR.

BY MAT ORNEY.

Patented Jan. 2, 1940 UNITED STATES PATENT OFFICE 2,185,469 I saw-sameWRAPPER.

Application October 19, 1936, Serial No. 106,337

1 Claim.

This application relates to self-sealing wrappers of waxed paper or thelike.

A self-sealing wrapper, as commonly known, comprises a sheet of waxedpaper, namely, a

sheet of paper having surface coatings of wax, folded over the object tobe wrapped, such as a loaf of bread, so that the edges of the wrapperare lapped, and the wax coating on the surface of one lap is intended tobe fused to the engaged surface of the adjacent lap to form a sealedwrapper. 4

For various reasons which need not here be enumerated, objections havebeen found to wrappers commonly claimed to be self-sealing wrappers,principally on the grounds that it is difficult to produce wrapperswhich can be relied upon to seal themselves in every instance when runthrough automatic high speed wrapping machinery, such as Hayssen,Standard, or Battle Creek machines. I

It is observed here that unless such reliance can be had, the use ofso-called self sealing wrappers in automatic high speed wrappingmachinery is not encouraged, for the reason that the wrappers aroundobjects coming out of the wrapping machine will not in every case besealed satisfactorily.

By my invention I have provided a self-sealing wrapper which can beproduced easily and with so well-known methods of producing waxed paperin sheets and rolls suitable for use in automatic wrapping machinery,with the paper being so constructed that the user thereof may restassured that every wrapped object coming out of 35 the wrapping machinewill be wrapped in a sealed wrapper, all without the necessity forchanging in'any 'way the operations of wrapping or the functions of thewrapping machines.

For an understanding of my invention refer- 40 ence should be had to theappended drawings disclosing embodiments of the same. In these drawings,

Fig. 1 shows a loaf of bread wrapped in a Hayssen wrapping machine withthe wrapper 45 comprising a self-sealing wrapper of the invention;

Fig. 1a shows the wrapped loaf of Fig. 1 in the obverse position, thelapped sealed edge of the wrapper being visible;

50 Fig. 1b shows a loaf of bread wrapped in a Standard or Battle Creekwrapping machine with the wrapper comprising a self-sealing wrapper ofthe invention;

Figs. 2 and 2a show fragments of the strips 6 as they go into Hayssen orStandard or "Battle Creek wrapping machines and indicate the structuraldetails that make my wrapper a selfsealing wrapper;

Fig. 3 shows a modification of the strip;

Fig. 4 shows in cross section and to greatly 5 enlarged scale strips ofself-sealing wrapper stock;

Figs. 4a and 4b show in cross section lap joints formed by the use ofstrips of the character disclosed in Fig. 4.

The wrapper of my invention comprises little more than a sheet of waxedpaper similar in quality, type, and size to those now used. Thesewrappers are generally formed in rolled sheets which are fed intoautomatic wrapping machines 15 such as Hayssen, Standard, or BattleCreek machines, where they are cut off into unit lengths and the cutlengths are then folded and wrapped about the object to be wrapped, suchas the loaf of bread herein shown, and in wrapping the sheet 20 aboutthe loaf the edges of the sheet are lapped over each other to form a lapseal.

In the use of self-sealing wrappers, both those presently known andthose of my invention, the lapping edges of the strip are heated during25 the wrapping operation with the intention of having the wax coatingson these lapping edges fuse to one another to seal the edges to eachother and thus form a self-sealed wrapper. For various reasons thispractice does not always produce a' self-sealed wrapper in the case ofwrappers now known. After an intensive and prolonged study I havediscovered that a very simple way to produce a self-sealing wrapper isto provide in the lapping edges quantums of wax in addition to thosecarried on the wax sheet as surface coatings, and these excess quantumsof wax, when heated in the wrapping machine, perform the function offusing to one another whereby a seal is automatically produced. While 40in the preferred embodiments these excess quantums are formed in each oftwo adjacent laps, it will readily be understood that if desired theseexcess quantums may be formed in one lap only, to fuse with surface waxof the other lap.

In the strip of Figs. 2 and 2a these excess quantums are in the natureof wax plugs l0 filling perforations in the strip ll. These perforationsare produced in the strip before waxing, so that when the strip'ispassed through the waxing bath and becomes coated with wax [2 on itssurface, the perforations in addition become filled with wax plugs Ill.When the edges l3 are lapped over each other the wax plugs of one lapwill register with those of the other and fuse to form wax rivets 14,all as indicated in Figs. 4 and 4a. Where the plugs do not register withone another, as might very well be the case, the plugs of one lap mightfuse with the surface coatings of the other, all as indicated in Fig.4b, which shows the plugs l0 fused to surface coatings I2 because theydo not register with one another.

To increase the possibility that the plugs of one lap will register withthose of the other so as to form rivets of the character indicated inFig. 4a, the perforations need not be placed in even rows as shown inFig. 2 but might be placed in staggered and scattered arrangements asshown in Fig. 3 and it will be observed that when the edges of the stripof Fig-.3 are lapped some of the plugs of one lap are bound to registerwith some of the plugs of the other lap, with .the result that waxrivets of the character of Fig. 4a will necessarily be formed, eventhough some of the plugs of' one edge do not register with some of theplugs of the other edge; these non-registering plugs will then fuse tothe surface coatings as shown in Fig. 4b.

It has been discovered that in some instances some of the perforationsdo not become filled with wax and remain unfilled; when these registerwith other unfilled perforations, as is undoubtedly the case in manyinstances, the inlating holes.

terior of the wrapper may ventilate itself through these perforations.This is of advantage when the wrapper is used with foods which should beaerated when wrapped, and a notable instance of this is the bread loafshown.

This feature may be provided by providing rows of perforations at eachedge of the wrapper strip far enough away from that edge to avoid beinglapped by the other edge when the wrapper is folded around the loaf-andby making certainthat such rows of perforations are left unfilled withwax-so thatthey will provide venti- Now having described theself-sealing w rapper shown herein in its various modifications,reference will be had to the'claim which folloyvs for a determination ofthe protection sought by this application.

I claim:

A self-sealing wax coated paper wrapper comprising a sheet of wax coatedpaper folded over the object to be wrapped and having its edges lapped,with the laps having a multiplicity of registering perforations filledwith wax integral with the wax of the coating, these wax fillings of theholes forming integral wax rivets which bond to one another and to thecoating and rivet the laps to each other.

WILLIAM NIAL MAoDONALD.

